"Our biggest challenge with hazard reduction is the weather and the windows available to do it safely and effectively," Mr Fitzsimmons said in an interview on Sunrise.

"Sure, there's environmental and other checks to go through but we streamline those. There's special legislation to give us clearance and to cut through what would otherwise be a very complex environment."

Andrew Strunk took to his Facebook yesterday and, in a post that’s since gone viral, busted some widely spread myths about the fires, their causes and apparent barriers to mitigation.

Mr Fitzsimmons said longer and hotter summers - contributed to by climate change - mean the window for hazard reduction burning is shorter each year.

That's widely accepted among firefighters, including Drew, who said weather extremes and drought made the jobs of fireys hard.

"Yes, conditions have been so bad this season that fires have still burnt through areas where hazard reduction burns were completed earlier in the year," he said.

But he also said governments needed to invest significantly more in hazard reduction burns.

"NSW for example, as an estimate, would need to increase their budget from $100 million to a half billion, a five fold increase and that money needs to come from somewhere," he said.

NSW RFS Commissioner Shane Fitzsimmons said the barrier to hazard reductions burns was the narrowing window of time to conduct them – not environmentalists. Picture: AAP

He also rubbished another suggestion spread on social media that environmentalists had 'locked up' national parks and nature reserves.

"Yes, (they) need to burn too but are hard to," Drew said.

"They are the (sanctuaries) for Australian fauna who can no longer survive in the farmlands and housing estates we've constructed. Indiscriminate burning of national parks will literally wipe species off the face of the earth as they often have nowhere else to go."

And he went on to challenge both sides of the political spectrum to look outside their social media and news consumption bubbles.

"No, a video on Facebook of a guy in the bush screaming at the greens is not facts about what caused these fires. No, a video of someone shouting at ScoMo for not funding the NSW Rural Fire Service (state gov funded) is not facts about what caused these fires."

Opponents to action on climate change have taken to social media and the comments sections of news websites, including news.com.au, to attack the suggestion that bushfires demonstrate more should be done to reduce emissions.

"Yes, climate change is contributing to a longer fire season. Yes, we should have acted on climate change long ago. All of us. The whole world. Everyone.

"No, no one knows exactly how much climate change has contributed to exacerbating the conditions for this year's catastrophic fire season however the best science available and scientific consensus is that there is an undeniable link."

Bizarre conspiracy theories about the bushfires are spreading on social media.

Bizarre conspiracy theories about the bushfires are spreading on social media.

The University of Queensland lecturer in critical thinking Peter Ellerton believes the spread is thanks to people looking for information that confirms their existing beliefs.

"This is a wonderful example of 'motivated reasoning', where we justify how we hold onto a world view that's served us in the past but as the evidence mounts against it," Dr Ellerton told news.com.au.

"The attempts to preserve it are becoming more and more disparate and chaotic. You see this kind of thing happening more intensely."

There are organised groups of people, institutions and even commercial interests who are "very eager" for people to find reasons to maintain their views, Dr Ellerton said.

The fire in the bush near Mudgee was owned by Energy Australia. Sold for carbon credits. imo, if the gov is going to sell off large swathes of bush so conglomerates can do their environmental "duty", then lock that bush up, they should be responsible for fighting the fires within

Queensland University of Technology researcher Timothy Graham has probed more than 300 Twitter accounts that have been posting about the bushfires using the hashtag #ArsonEmergency.

He found that one-third displayed bot-like behaviour - the automated spread of inauthentic information about how the bushfires started.

The idea that most, if not all of the fires were started by firebugs is false. While police have charged dozens of arsonists, the figure is much lower than the "hundreds" being cited.

Some even shared fake news articles 'reporting' that climate change activists had deliberately lit bushfires to prove their point.

"The motivation underlying this often tends to not be changing people's opinions about the bushfire itself and how it's happening, but to sow discord and magnify already existing tensions in polarised political issues," Dr Graham told the ABC.

Bizarre conspiracy theories about the bushfires are spreading on social media.

Other viral posts on Facebook about the bushfires have spread bizarre conspiracy theories that the government is responsible for the fires, lit to clear land to make way for high-speed rail.

Some posts have even suggested that Muslims have lit them as some kind of jihadist terror attack.

"That stuff is only shocking if you begin with the assumption that people make decisions based on facts," Dr Ellerton said.

"They don't. And we seldom have.

"We're far more persuaded by narratives than we are by facts. Facts are important, there's no question about it, but they're not enough."

He said that sometimes, people don't care if something isn't true so long as it perpetuates their ideology or point of view.

"In a world where so much of it is known and so little of it by you, it's comforting to have your own world views massaged by lots of people," Dr Ellerton said.

Bizarre conspiracy theories about the bushfires are spreading on social media.